Electric motor mount for sewing machines

ABSTRACT

A mounting arrangement for pivotally supporting an electric motor within the casing of a sewing machine with provision for angular adjustment of the motor to regulate the tension in a belt by which the motor drives the sewing machine and in which the pivotal motor support is arranged to provide for maximum belt tension adjustment with minimum disturbance in the registration of an electrical connector socket on the motor relatively to a clearance opening for the electrical connector in the sewing machine casing.

United States Patent 11 1 Herron et al.

, ELECTRIC MOTOR MOUNT FOR SEWING MACHINES [75] inventors: William L.Herron, North Caldwell; Kenneth D. Adams, Madison, both of [73]'Assignee: The Singer Company, New York,

[22] Filed: May-l, 1972 [21] Appl. No.: 249,331

'[52] US. Cl. 112/220 [51]- Int. Cl. D05b 69/12 [58] Field 0! Search112/220, 221, 219 R,

112/218 R; 248/16; 3l0/9l 56] I References Cited I UNITED STATES PATENTS3,141,429 7/1964 Momberg et a1. 112/220 June 19, 1973 3,157,142 ll/l964Birchetal. ..ll2/220 Ewm MPH-flempwn un e Attorney- Marshall J. Breen,Chester A. Williams,J r. and Robert E. Smith [57] ABSTRACT A mountingarrangement for pivotally supporting an electric motor within the casingof a sewing machine with provision for angular adjustment of the motorto regulate the tension in a belt by which the motor drives the sewingmachine and in which the pivotal motor sup port is arranged to providefor maximum belt tension adjustment with minimum disturbance in theregistration of an electrical connector socket on the motor relativelyto a clearance opening for the electrical connector in the sewingmachine casing. I

3 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION It isconventional in the sewing machine art to provide a separable plug andsocket connection in the electrical wiring for the electric sewingmachine driving motor so that the supply cord and the speed controllercan be detached when it is desired to store or transport the sewingmachine. It is also known to form the socket of such separableelectrical connection as a part of the electric motor housing, and wherethe electric motor is supported exteriorly of the sewing machine casing,this arrangement does not present any particular problems.

When the electric motor is to be arranged within the machine casing,however, adjustment of the motor into proper driving relationship, asfor instance to regulate Y belt tension, also shifts the socket of theelectrical connection. In order to accommodate the plug in all possiblesocket positions, a large clearance aperture is required in the sewingmachine casing which is not only unsightly but which can exposeoperating mechanism within the casing.

SUMMARY OF THE INVENTION electrical connection socket cooperable with anelectrical plug adapted to engage the socketthrougha minimum sizedclearance opening in the sewing machine casing. This object of theinvention is attained by locating the electrical socket remote from themotor drive shaft and by providing pivotal support means for the motorclosely adjacent to the electrical socket. Maximum repositioning of themotor shaft for belt tension adjustment can thus be attained withminimum shift of the position of the electrical socket.

DESCRIPTION OF THE DRAWINGS This invention is illustrated in theaccompanying 1 drawing of a perferred embodiment in which:

FIG. 1 represents an end elevational view of a sewing machine havingthis invention applied thereto with portions of the sewing machinecasing broken away,

FIG. 2 is a bottom plan view of the sewing machine of FIG. 1 with thesewing machine bed casing removed, and 1 FIG. 3 is a cross sectionalview taken substantially along line 3-3 of FIG. 1. i

In the accompanying drawings a sewing machine is illustrated indicatedgenerally at 11. The sewing machine includes a frame 12 in which theoperating mechanism of the sewing machine such as a main shaft 13 issupported. The sewing machine is also provided with an exterior casing14 which may be formed as a portion of the frame 12 or which may beprovided as a separate element covering the frame.

For driving the sewing machine, an electric motor indicated generally at20 is provided. In accordance with this invention, the motor 20 ismounted on the sewing machine frame within the casing 14, and a driveshaft 21 of the electricmotor carries a pulley 22 on which is entraineda belt 23 which drivingly engages a sprocket 24 on the main shaft 13 ofthe sewing machine.

The electric motor 20 is constructed with a housing preferably formed ofan insulating material such as molded synthetic plastic or the like. Thehousing is formed integrally with an electric socket 31 in whichterminals 32 for electric wiring of the motor as well as any ancillaryelectrical equipment (not shown) such as lighting devices or the likemay be directed. The socket 31 is adapted to accommodate a plug 33 whichcarries prongs as engageable with the terminals 32 thus to provide aseparable electric connector so that conductor 35 to a source of supplyas well as to a speed controlling instrumentality (not shown) may bereadily disconnected from the sewing machine as for storage, transportor the like.

The sewing machine casing 114 is formed with a clearance aperture 40 forthe plug 33 which, as best shown in FIG. 3, is arranged in registry withthe socket 31 and for appearance and safety should be as small as ispossible.

The motor mounting of this invention provides for minimum size of theclearance aperture 40 commensurate with a maximum range of adjustment ofthe position of the motor drive shaft for belt tension regulation. Themotor mount includes a pair of axially aligned pivot pins and 51 whichare secured in lugs 52, 53 respectively on the machine frame, and whichare enhanced by apertured bosses 54, 55 on the motor housing. Forsecuring the pivot pins 50 and 51 in the machine frame lugs 52, 53, anarrangement as shown in FIG. 3 may be used in which the sewing machineframe lug 52 is formed with a transverse plot 56 within which issituated a spring clip 57 which is snapped onto the pivot pin 50.

The aligned pivot pins 50, 51, as shown in FIG. 1, engage the motorhousing closely contiguous to the electric connector socket 331 so thatdespite pivoted movement of the motor 20, the socket will move onlyslightly relatively to the clearance aperture 40 and the aperture needonly be slightly larger than the plug in order to accommodate the plugin any of a wide range of different angular positions of the motor.

The drive shaft 21 of the motor is preferably arranged at a greaterdistance from the pivot pins 50 and SI than the socket. This remoteposition of thedrive shaft provides for increased shift of the driveshaft position when the motor is shifted angularly about the axis of thepivot pins 50 and 51.

For regulating the angular position of the motor 20,

- the motor housing 30 is formed, at the side of the drive shaftopposite the socket 311', with a guideway 60 which extends radially ofthe pivotal axis defined by the pivot pins 50, 51. Extending into theguidway 60 is a crank pin 61 carried eccentrically on a threaded stud 62which is constrained in a threaded bore 63 in a lug 64 on the sewingmachine frame. A lock nut 65 serves selectively to clamp the stud 62 inany selected position of the crank pin. Preferably, the guideway 60 andthreaded stud 62 are arranged at the opposite side of the motor driveshaft 21 from the socket 31.

Having set forth the nature of this invention, what is claimed hereinis:

I. In a sewing machine having-a frame with a casing, an electric sewingmachine driving motor having a housing, a drive shaft projectingexteriorly of said housing and an electrical socket carried on saidhousing, means for shiftably supporting said electric motor within saidsewing machine casing comprising interengaging pivot means on saidsewing machine frame and on said electric motor housing remote from saiddrive means and said electrical socket are arranged at one side of saiddrive shaft and said motor locating means is arranged at the oppositeside of said drive shaft.

3. In a sewing machine as set forth in claim 2 in which said motorlocating means comprises a guideway formed in said motor housingsubstantially radially of said pivot means, and a crank pin adjustablysecured in said sewing machine frame and engaged in said guideway.

4: Ir a

1. In a sewing machine having a frame with a casing, an electric sewingmachine driving motor having a housing, a drive shaft projectingexteriorly of said housing and an electrical socket carried on saidhousing, means for shiftably supporting said electric motor within saidsewing machine casing comprising interengaging pivot means on saidsewing machine frame and on said electric motor housing remote from saiddrive shaft and contiguous to said electrical socket, and shiftablemotor locating means on said sewing machine frame and said motor housingremote from said electrical socket, said sewing machine casing beingformed with an electrical plug accommodating clearance aperture arrangedin registry with said electrical socket on said motor housing.
 2. In asewing machine as set forth in claim 1 in which said pivot meanssupports said motor housing on an axis Parallel to said drive shaft, andin which said pivot means and said electrical socket are arranged at oneside of said drive shaft and said motor locating means is arranged atthe opposite side of said drive shaft.
 3. In a sewing machine as setforth in claim 2 in which said motor locating means comprises a guidewayformed in said motor housing substantially radially of said pivot means,and a crank pin adjustably secured in said sewing machine frame andengaged in said guideway.